The present invention relates to the field of surgical instruments for spinal stabilisation operations using bone-anchor elements such as screws by a posterior or posterolateral approach.
The invention relates specifically to an instrument kit according to the invention intended mainly, but not exclusively, for lumbar, thoracic or even posterior cervical spinal osteosynthesis surgery, by minimally invasive or open surgical approaches.
In the event of anatomical malfunctions of the spinal column, bone anchors such as pedicular or vertebral screws are placed in the vertebra, connected to one another by connection elements such as rods or plates.
Prior Art
Application PCT/FR10/000880, by the applicant, is known from the prior art. Said document discloses instrumentation for fixing at least two spinal vertebrae by bone-anchor implants such as pedicular screws including a bone-anchor element intended for being fixed to a vertebra, pre-mounted on a disposable mounting tube, and a sealed sterile packaging container.
Said prior art document also relates to a kit of instruments for installing or removing a spinal implant comprising at least two threaded bone-anchor elements, a connecting member such as a rod or a plate mechanically connecting the bone-anchor elements and locking elements for locking the connecting member in position relative to the anchor elements, in order to perform all the surgical deeds linked to the installation or removal of said implant, characterised in that all of said necessary instruments are disposable and packaged under sterile conditions in one or more sealed containers.
French patent FR2874496 is also known, describing a retractor for the tissues of a patient, of the type including two blades having a proximal end and a distal end, respectively, said blades being arranged such as to form an surgical channel open at the proximal and distal ends of said blades, characterised in that the retractor comprises at least one matching blade to form a retractor with at least three blades, said blades separating from one another by pivoting of the distal ends thereof such as to form a tapering widened surgical channel.
European patent application EP0455282 is also known, describing an autostatic separator including a polygonal winder frame connected to a plurality of dilators.
When inserted deeply into the body of the patient, it keeps the edges of the incision open. The sides are hingedly connected to one another and to two opposing hinges.
Another example of a separator is described in U.S. Pat. No. 3,509,873.
Drawbacks of the Prior Art
Said prior art retractor solutions have two major drawbacks. First of all, these solutions lead to two separate devices:                one or more tubes making it possible to support the spinal screw and, during the intervention, to guide the linking rod which is inserted in the screw head, and then to insert and screw a plug locking the rod in the screw head;        a second device made up of a plurality of blades capable of holding the tissues in the area around the operating area.        
In the prior art solutions, said known devices take up a considerable amount of space in the surgical area, which makes it necessary either to widen the incision, or to make do with a narrow field of vision and work. In both these cases, the surgeon is impeded in the execution of the operation and the surgical deed.
The second drawback is that the second device must be positioned prior to inserting the screws. Once it is placed in the operating area, the device limits the possible angulation of the tubes and thus complicates spinal screwing and the insertion of the proximal end of the tube on the spinal screw when the screw is not pre-mounted on the tube.
Finally, in all the prior art solutions, the retractor (second device) is a complex surgical instrument, requiring thorough, complicated sterilisation, given the complex shapes and the presence of multiple hinged sections, after each use. Said complex additional device furthermore creates an additional cost which is difficult to afford given the economic constraints of the healthcare industry.